Tungsten Alloy 90W-7Ni-3Cu
ASTM B777 Class 1
Liquid-phase sintered tungsten heavy alloy with a nickel-copper matrix binding hard tungsten grains, offering very high density and good machinability for radiation shielding and balance weight applications.
Reference datasheet — 90W-7Ni-3Cu is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
90W-7Ni-3Cu tempers and conditions
90W-7Ni-3Cu is supplied in 3 conditions, soft to hard.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress relieved | Choose for thin-walled or tightly toleranced machined parts where residual stress would cause distortion. | 520 | 690 | 4 | 25 HRC | 15 % IACS |
Sintered plus vacuum/hydrogen anneal and rapid cool | Pick when maximum ductility and impact resistance are required, e.g. dynamic counterweights or parts that see handling shock. | 560 | 740 | 6 | 26 HRC | 15 % IACS |
Cold worked | Only for small-diameter rod/wire where higher strength and stiffness matter more than ductility; reductions are much smaller than for W-Ni-Fe grades. | 800 | 900 | 1.5 | 34 HRC | 14 % IACS |
Supply forms, finishes and certifications
Ways 90W-7Ni-3Cu is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ASDefault | As-sintered | Coating |
What is 90W-7Ni-3Cu?
Liquid-phase sintered tungsten heavy alloy with a nickel-copper matrix binding hard tungsten grains, offering very high density and good machinability for radiation shielding and balance weight applications. 90W-7Ni-3Cu has a density of 17 g/cm³ (0.614 lb/in³), lighter than 74% of tungsten alloy grades. It melts at 1,400°C (2,552 °F). 90W-7Ni-3Cu has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 3% and the elastic modulus is 320 GPa (46.4 Msi).
What is 90W-7Ni-3Cu used for?
- radiation shielding
- collimators
- counterweights
- vibration damping masses
Advantages
- Easy to machine — 40/100, better than 98% of tungsten alloy grades
- Tough — resists crack growth — 40 MPa·√m (36.4 ksi·√in), better than 86% of tungsten alloy grades
- Low embodied carbon — 21 kg CO₂/kg, better than 86% of tungsten alloy grades
Limitations
- Limited service temperature — 400°C (752 °F), worse than 98% of tungsten alloy grades
- Hard to polish — 55/100, worse than 98% of tungsten alloy grades
- Low stiffness — 320 GPa (46.4 Msi), worse than 90% of tungsten alloy grades
- Low strength — 550 MPa (79.8 ksi), worse than 89% of tungsten alloy grades
- Needs corrosion protection — 45/100, worse than 86% of tungsten alloy grades
90W-7Ni-3Cu properties
Typical room-temperature values; bars are the position among tungsten alloy grades.
Physical2
90W-7Ni-3Cu has a density of 17 g/cm³ (0.614 lb/in³), lighter than 74% of tungsten alloy grades. It melts at 1,400°C (2,552 °F).
Mechanical16
90W-7Ni-3Cu has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Elongation at break is 3% and the elastic modulus is 320 GPa (46.4 Msi).
Thermal5
90W-7Ni-3Cu is rated for continuous service to 400°C (752 °F). It conducts heat at 95 W/m·K (54.9 BTU/hr·ft·°F), worse than 71% of tungsten alloy grades. Thermal expansion is 5.2 µm/m·K (2.89 µin/in·°F).
Electrical3
90W-7Ni-3Cu conducts electricity at 15 % IACS, worse than 69% of tungsten alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 86% of tungsten alloy grades.
Sustainability4
Producing a kilogram of 90W-7Ni-3Cu takes about 300 MJ of energy and emits 21 kg of CO₂ — less than 88% of tungsten alloy grades. Typical recycled content is 25%.
Manufacturability7
90W-7Ni-3Cu's machinability is fair (40/100, better than 98% of tungsten alloy grades); weldability not recommended (12/100); formability not recommended (10/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the tungsten alloy family
Yield strength against density for every tungsten alloy grade FabDigit runs. 90W-7Ni-3Cu is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 90W-7Ni-3Cu
Is 90W-7Ni-3Cu easy to machine?
Turn/mill with rigid setups, sharp negative-rake carbide (or CBN for finishing), low speed and heavy flood coolant; the material is abrasive and chips are short and brittle — avoid interrupted cuts on thin sections.
Can 90W-7Ni-3Cu be welded?
Fusion welding cracks and coarsens the tungsten skeleton — join by Ag-Cu brazing, electron-beam/inertia welding with qualified procedures, or by screws, pins and shrink fits.
Can 90W-7Ni-3Cu be formed, bent or molded?
Made only by press-and-sinter (liquid-phase sintering at ~1400–1500 °C); the W-Ni-Cu matrix tolerates very little cold work, so near-net pressing plus machining is the normal route.
90W-7Ni-3Cu chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| WASTM B777 Class 1 nominal 90 wt% tungsten | 89 – 91 | 90 |
| Nimatrix former, Ni:Cu ≈ 7:3 | 6.3 – 7.7 | 7 |
| Cukeeps the binder non-magnetic | 2.7 – 3.3 | 3 |
| Feimpurity limit; Fe would make the matrix magnetic | ≤ 0.2 | |
| Other (each)C, O, Si, Ca impurities | ≤ 0.1 | |
| Ni+Cu matrixbalance to 100 wt% | balance |
What surface finishes work on 90W-7Ni-3Cu?
Grind/lap for tight tolerances; electroless or electrolytic nickel plating (5–20 µm) is standard for corrosion protection and to prevent staining on handled shielding parts.
Equivalent designations
Standards and trade names that resolve to Tungsten Alloy 90W-7Ni-3Cu in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B777 Class 1
- Also called
- WNiCu 90-7-3
How much does 90W-7Ni-3Cu cost?
90W-7Ni-3Cu is a high-cost tungsten alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
90W-7Ni-3Cu — frequently asked
What is 90W-7Ni-3Cu used for?
90W-7Ni-3Cu is typically used for radiation shielding, collimators, counterweights and vibration damping masses. In short: very high density metal; machinable tungsten heavy alloy; lead-free shielding material.
What is the yield strength of 90W-7Ni-3Cu?
90W-7Ni-3Cu has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 89% of tungsten alloy grades. Strength varies by condition: see the 3 listed tempers.
Is 90W-7Ni-3Cu easy to machine?
Not especially — machinability is rated fair (40/100, better than 98% of tungsten alloy grades). Turn/mill with rigid setups, sharp negative-rake carbide (or CBN for finishing), low speed and heavy flood coolant; the material is abrasive and chips are short and brittle — avoid interrupted cuts on thin sections.
Can 90W-7Ni-3Cu be welded?
Not readily — weldability is rated not recommended (12/100). Fusion welding cracks and coarsens the tungsten skeleton — join by Ag-Cu brazing, electron-beam/inertia welding with qualified procedures, or by screws, pins and shrink fits.
What surface finishes work on 90W-7Ni-3Cu?
Grind/lap for tight tolerances; electroless or electrolytic nickel plating (5–20 µm) is standard for corrosion protection and to prevent staining on handled shielding parts.
Can 90W-7Ni-3Cu be formed, bent or molded?
Made only by press-and-sinter (liquid-phase sintering at ~1400–1500 °C); the W-Ni-Cu matrix tolerates very little cold work, so near-net pressing plus machining is the normal route.
What is the maximum service temperature of 90W-7Ni-3Cu?
90W-7Ni-3Cu is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 90W-7Ni-3Cu cost?
90W-7Ni-3Cu is a high-cost tungsten alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B777 Standard Specification for Tungsten Base, High-Density Metal — ASTM International (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Tungsten Heavy Alloys) — ASM International (1990)
- Tungsten heavy alloy product datasheets (Plansee, Mi-Tech Metals, Midwest Tungsten Service, / ) — various producers (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.